Contents:

1. Programming and interface of touch sensor
1.1 What is the interface between the touch sensor and the microcontroller (such as Arduino)
1.2 How can I control the touch sensor through programming
2. Troubleshooting and maintenance of touch sensor
3. Purchase guide for touch sensors
3.1 How to choose a touch sensor
3.2 Which brands and suppliers provide high quality touch sensors
4. Conclusion

In the last blog post, we covered how the different types of touch sensors work and their respective pros and cons. Next, in this article, we will continue to discuss touch sensor programming and interface technology, troubleshooting and maintenance tips, but also provide information on how to choose the right touch sensor and recommend some quality brands and suppliers. Hopefully, this will help you understand touch sensors more fully.

1. Programming and interface of touch sensor

1.1 What is the interface between the touch sensor and the microcontroller (such as Arduino)

Common interface modes include:

Analog Input:

For some simple resistive touch sensors, they can be connected to a microcontroller via analog input pins. The touch sensor produces a voltage change that is read by an analog pin.

Example: Using ArduinoanalogRead()The function reads the analog input.

Serial Peripheral Interface (SPI) :

SPI is a synchronous serial interface for high-speed data transmission. Many modern touch screens and sensors use the SPI protocol to communicate with microcontrollers.

Example: Using Arduino's SPI library for initialization and data exchange.

Two-wire serial interface (I²C/TWI) :

I²C is a bidirectional, two-wire serial communication protocol used to connect low-speed microcontrollers and peripherals. Many touch sensors support the I²C protocol.

Example: Use Arduino's Wire library for initialization and data exchange.

Universal Asynchronous Transceiver (UART/Serial) :

UART allows devices to exchange data asynchronously over serial communication links. Some advanced touch sensors may use UART for data transmission.

Example: Data sending and receiving using Arduino's Serial library.

Special interface:

Some touch sensors may have specialized interfaces or protocols that need to be controlled using specific libraries or drivers.

Example: Connect a touch sensor using Arduino

Analog input example

int touchPin = A0; // Assume that the touch sensor is connected to A0 void setup() {Serial.begin(9600); } void loop() { int touchValue = analogRead(touchPin); // Read the analog value of the touch sensor Serial.println(touchValue); } 

SPI interface Example

#include <SPI.h> #include <Adafruit_FT6206.h> Adafruit_FT6206 ts = Adafruit_FT6206(); void setup() { Serial.begin(9600); ts.begin(); } void loop() { if (ts.touched()) { TS_Point point = ts.getPoint(); Serial.print("X: "); Serial.print(point.x); Serial.print(", Y: "); Serial.println(point.y); } } 

I²C interface example

#include <Wire.h> #include <Adafruit_Touchscreen.h> Adafruit_Touchscreen ts = Adafruit_Touchscreen(); void setup() { Serial.begin(9600); ts.begin(); } void loop() { if (ts.touched()) { TS_Point point = ts.getPoint(); Serial.print("X: "); Serial.print(point.x); Serial.print(", Y: "); Serial.println(point.y); } } 

1.2 How can I control the touch sensor through programming

Programming to control a touch sensor usually involves the following steps:

a. Select programming language and development environment:

Choose the right programming language based on your development platform and personal preference, such as C/C++, Python, etc.

Use the appropriate development tools, such as Arduino IDE, Visual Studio Code, Eclipse, etc.

b. Install the necessary libraries and drivers:

Get and install the library file or driver for the touch sensor you are using. These are usually provided by sensor manufacturers and can also be found from the open source community.

c. Initialize the touch sensor:

Initialize the touch sensor in the code, set the necessary parameters such as communication protocol (I2C, SPI, etc.), pin configuration, etc.

d. Read touch data:

Write functions to read the status information of the touch sensor, such as touch position coordinates, touch status (press, release, etc.).

e. Handling touch events:

Perform corresponding actions based on the read touch data, such as drawing graphics on the display and sending commands to other devices.

f. Implement user interaction logic:

Write user interaction logic based on application requirements to handle touch input and other user behaviors.

Here's a simple example, assuming we're using an Arduino-based platform with capacitive touch sensors:

#include <Adafruit_Touchscreen.h> // Initializing Touchscreen objects Adafruit_Touchscreen ts = Adafruit_Touchscreen(); void setup() {// Initializing Serial communication serial.begin (9600); // Initialize the touch screen ts.begin(); } void loop() {// Read touch coordinates TS_Point p = ts.getPoint(); // Check whether a touch event occurs if (p.z > 0) {// z indicates the touch intensity, and a value greater than 0 indicates the touch Serial.print("X: "); Serial.print(p.x); Serial.print(", Y: "); Serial.println(p.y); // Add code here to handle touch events}} 

In this example, we useAdafruit_TouchscreenLibrary to initialize and read touch sensor data. Depending on the touch coordinates (p.x, p.y), specific logic can be further implemented in the program, such as moving a pointer on the screen or executing a certain command.

If you are using another platform or language, similar steps will apply, but the specific libraries and apis will be different. It is important to understand how to initialize the device, read the data, and process that data to implement the desired functionality.

2. Troubleshooting and maintenance of touch sensor

Touch sensors may encounter a variety of problems during use, and understanding these problems can effectively diagnose and solve various problems that may occur during the use of touch sensors.

Here are some common problems and their solutions:

Hardware problems

No response to touch:

Diagnostics: Check that the power supply is normal and confirm that the touch sensor is properly connected to the microcontroller.

Solution: Reconnect lines to ensure all connections are secure; Check whether the power cable is loose or damaged.

Inaccurate touch:

Diagnostics: See if the touch calibration is correct and check for physical damage or dirt covering the sensor surface.

Solution: Recalibrate touch sensor; Clean the surface of the touch panel to remove dust or stains.

Touch drift:

Diagnosis: It may be caused by aging of internal components of the sensor or environmental factors.

Solution: Replace the sensor; Improve working environment to avoid extreme temperature or humidity.

Hardware failure:

Diagnosis: The internal components of the touch sensor may be damaged.

Solution: Contact the manufacturer or maintenance professional to repair or replace the touch sensor with a new one.

Software problems

Driver problem:

Diagnosis: Abnormal touch function, possibly due to driver error or obsolescence.

Workaround: Update or reinstall the driver.

Firmware error:

Diagnosis: Touch response is inconsistent or abnormal behavior occurs.

Solution: Update firmware to latest version; If possible, reset the firmware to factory Settings.

Software compatibility issues:

Diagnosis: The touch feature does not work in some operating systems or versions.

Resolution: Check touch sensor support and make sure operating system is up to date; Or look for alternatives.

Environmental issues

Electromagnetic Interference (EMI) :

Diagnosis: Electromagnetic interference sources, such as motors and wireless devices, exist in the surrounding environment.

Solution: Take shielding measures, such as using metal shells or shielding cables; Try to stay away from sources of interference.

Electrostatic Discharge (ESD) :

Diagnosis: The touch sensor is susceptible to static electricity.

Solution: Use anti-static pads and wrist straps, especially during installation or maintenance; Ensure that ESD protection measures are in place in the working environment.

Temperature and humidity:

Diagnosis: Extreme temperature or humidity can cause degradation of touch sensor performance.

Solution: Ensure that the working environment is suitable for temperature and humidity; Use touch sensors designed with environmental considerations in mind.

How to maintain the touch sensor on a daily basis

Check and clean the touch panel regularly to avoid dust and oil accumulation.

Regularly back up touch sensor setup and calibration data for quick recovery in case of problems.

For critical applications, monitor conditions such as temperature and humidity in the working environment to ensure they are within safe limits.

3. Purchase guide for touch sensors

3.1 How to choose a touch sensor

When shopping for a touch sensor, there are several factors to consider to ensure that you choose a product that meets your application's needs and is cost-effective.

Here are some key steps and considerations for choosing a touch sensor:

① Clear application requirements

Determine what functions the touch sensor needs to support, such as whether it needs to support multi-touch, whether it needs to support gesture recognition, and so on. Consider the environment in which the touch sensor will be used, such as whether it needs to be waterproof, dust resistant, and whether it needs to operate in extreme temperature conditions. Understand the habits and preferences of the target user group, such as whether it needs to support operation with gloves, whether it needs to be used outdoors in bright light, etc.

② Choose the right touch technology

Capacitive: Suitable for applications requiring high sensitivity and multi-touch, such as smartphones and tablets.

Resistive: Suitable for applications that require operation in harsh environments, such as industrial equipment or medical equipment.

Infrared: Suitable for large displays, such as billboards or public information stations.

Ultrasonic: Suitable for applications that need to work in special environments or require high precision.

Optical: Suitable for applications requiring large displays, such as conference tables or display tables.

③ Consider the sensor characteristics

Select sensors with the right accuracy for your application. For applications that require an immediate response, choose a sensor that responds quickly. Consider the durability of the sensor, especially for applications that require frequent use or work in harsh environments. Ensure sensor compatibility with existing systems, including hardware interfaces and software drivers.

(4) Cost-benefit analysis

Compare the procurement costs of different sensors. Consider the cost of long-term operation and maintenance, including energy consumption and repair costs. : Considering the initial investment and subsequent operation and maintenance costs, choose the scheme with the lowest overall cost.

Test and evaluation

Obtain samples where possible for actual testing to evaluate their performance and reliability. If possible, get feedback from potential or existing users on the sensor.

⑥ Supplier selection

Choose a supplier that can provide good technical support and service. Ensure that the supplier can provide stable supply and has good reputation. Consider the vendor's warranty policies and support services.

⑦ Comply with regulations and standards

Ensure that the selected touch sensors comply with the relevant standards and specifications of the industry. Comply with local laws and regulations. Choose sensors made of environmentally friendly materials to support sustainable development.

Through the above steps, you can more targeted the purchase of touch sensors, ensuring that the product you choose not only meets the needs of your current application, but also provides stable performance and user experience for some time to come.

3.2 Which brands and suppliers provide high quality touch sensors

There are many brands and suppliers on the market that offer high quality touch sensors. Here are some well-known suppliers and brands.

4. Conclusion

INFINITECH explains the key technologies of touch sensors and their programming interface schemes in practical applications, and provides sample codes based on the Arduino platform to help readers better understand and realize the integration of touch sensors. We also analyze in detail the various kinds of faults that the touch sensor may encounter in the process of use and their troubleshooting methods, which provides effective guidance for maintenance work. Finally, this paper presents a set of systematic purchasing guidelines, covering all aspects from application demand analysis to supplier selection, and recommends well-known suppliers and brands in the market. I hope this article will be a valuable resource for engineers and technology enthusiasts to help them achieve greater success in the field of touch sensing technology.